Mt. Saint Helens erupts in 1980: one side of the mountain collapses in a gigantic landslide (0:17)Via Google Video

Videos of small fires quickly turning into "flashovers" -- that is, when everything in the room bursts into flame all at once. With temperatures commonly 1,000 degrees or more, even firefighters in full gear would have only about 5 seconds to get out in order to survive. This shows why it's important to GET OUT when there's a fire, even if it looks small at the moment.

A dried Christmas tree turns into a blowtorch in 5 seconds, and has the whole room burning in another 30 seconds. Via Citizen Corps